All these tools are activated by indirect firing, with a drive piston, specifically a fastening plug or nail, where the piston is propelled forwards until its head is crushed against a damper.
All these tools can withstand numerous impacts, essentially two at each firing, one at the moment of ignition, when a gas apparatus or cartridge is involved, and another when the piston is crushed against the damper.
Crushing of the piston against the damper can cause a second impact:    a) shortly after the first one, which is a significant impact, in the event that it is fired when empty;    b) a bit longer afterwards, but still relatively significant for a scenario involving a short nail or a delicate material;    c) a longer time afterwards, for a long nail or hard material or    d) an even longer time afterwards, in the case of a long nail or very hard material.
In the first case, a), the apparatus is very clearly over-powered, in the second case, b), it still is, but less so, in the third case c), the apparatus is only very slightly over-powered and finally, in the fourth case d), the apparatus is under-powered.
Using an under-powered apparatus is no more desirable than using an over-powered one, since this could lead to deterioration and cause premature wear. It is even worthwhile to alert an operator of the apparatus in case of intensive use with more or less than ideal power, and even to prevent him from continuing to use his apparatus.